Investigations on the lower causeway of the Bent Pyramid in Dahshur

Abstract

The Bent Pyramid at Dahshur plays a major role in the development of the Old Kingdom royal funerary complexes. From Ahmed Fakhry's excavations, the basic layout is known, including the pyramid and its temple as well as a stone-built causeway linking the pyramid precinct to a lower temple. According to Fakhry's plans it was also evident that a lower causeway, built from mudbrick, led from the valley to the temple. However, the course and design of this lower causeway remained unknown. Magnetometric prospection, hand auger sond- ages and excavation trenches in the wadi to the east of the Bent Pyramid revealed a lower causeway of mudbricks with a length of 141 m leading to the valley temple of the Bent Pyramid. In front of the lower causeway, in a distance of approximately 800 m from the present desert edge, a U-shaped structure of 145 x 95 m defined by mudbrick walls and open to the east is situated. We interpret this structure as harbour complex. This means that this temple should indeed be interpreted as valley temple. It is a major insight gained through the cooperation with physical geographers from the Free University Berlin that the wadi to the east of the Bent Pyramid changed its shape fundamentally in historictimes. In the valley up to 7 m of aeolian sand deposits accumulated and covered the lower causeway and the harbour afterthey were built in the Old Kingdom.The lower causeway, the harbour basin and the valley temple were built directly on the local shale (taffl) in the Old Kingdom. Transport ramps were most probably later used as foundations of the causeways. The harbour basin and the levelling of the southern valley slope changed the shape of the wadi fundamentally. The lower walking horizon of the wad; and the steep course of the lower causeway must have intensified the impression of a distant but however dominant pyramid complex. The walls of the lower causeway are well preserved to a height of 3.50 m. The lower causeway was originally open. According to the pottery the first construction phase can be dated to the early 4th Dynasty, presumably to the reign of King Sneferu. The causeway was vaulted in a second construction phase. Pottery sherds from the 6th Dynasty date this alteration to the 6th Dynasty. The vault is most probably to be interpreted as protection against the accumulating sand, but it can also be considered as modernisation. The aeolian dynamics started at the earliest in the second half of the 4th Dynasty and at the latest in the first half of the 5th Dynasty. In the middle of the Old Kingdom, the sand deposits outside the lower causeway already reached a height of at least 2 m. Deposits of beer jars and fire places to the north of the causeway proof that rituals were still performed during that time. In the 12th Dynasty, that means about 600-700 years after its erection, the causeway was almost completely covered by sand. At the end of the 18th Dynasty or at the latest at the beginning of the 19th Dynasty, the top of the causeway was covered in the area of the excavation trench with a sand deposit of 1.50 m. The valley temple was dismantled in this time. A transport way from rough limestone blocks was used to transport the large blocks from the temple to the floodplain. Several of the limestone fragments which were reused in the transport way were decorated. Until now we discovered about 70 additional relief fragments supplying important new information for the understanding of the decoration program of the valley temple of the Bent Pyramid.